Review on Houseables Picture Hanger Kit - Mirror Hanging Hardware, French Cleat, 3 Pair, 6 Inch, 50 lbs Capacity - Aluminum Z Bar Clip Rail Bracket - Wall Mount Hangers with Nails - White Board Mounting, Shelf, Art by Nicole Mcleod

.the problem is that they are designed to be attached to the photo frame with a small metal flange, which seems unreliable to me. So I drilled holes in the small flange so they will mesh much more securely when assembled. It worked very well, but it took a lot of effort to get to the perfect level. But in the end everything is fine. And maybe it would work just as well or even better if I used them as they were intended, but I just didn't feel comfortable (I don't want the photos to fall off in an earthquake).